摘要
Forward osmosis (FO) membranes, incorporating carbon blacks and carbon nanotubes derived from CO2, are fabricated and high structural stability and outstanding water flux of the FO membrane are achieved. Traditionally, most of the FO membranes used non-woven fabrics or porous polymers as support layers. However, thicker support layers with less porosity induces severe internal concentration polarization effect, resulting in a negative influence on FO performance. Herein, different pore sizes (0.2 and 0.45 μm) of mixed cellulose ester (denoted as MCE0.2 and MCE0.45, respectively) are adopted as support layers, providing proper initial porosity and excellent mechanical strength for the membranes. Moreover, acid-treated carbon nanotubes (aCNTs) derived from CO2 are employed as the interlayer to reduce the pore effect and roughness of the MCEx, thus facilitating the formation of a dense and continuous polyamide (PA) selective layer. Besides, different concentrations of treated carbon blacks (CBs) are incorporated into the PA layer to further enhance the membrane performance. Stability and durability tests using deionized water as the feed solution and 1 N sodium chloride as the draw solution show that MCE0.2/aCNT50/PA-CB0.4 demonstrates an outstanding performance, exhibiting a water flux of 50.63 LMH and a specific salt flux of 0.05 g/L, maintaining stable water flux in a 3-h test per cycle over 9 cycles in the repeatability test, demonstrating the application potential of the fabricated membrane for water supply from desalination toward global sustainability.
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•High-performance TFC membrane is prepared using CO2-derived CNTs and carbon blacks.•Thin MCE support greatly improves FO transport performance and lowers ICP.•aCNT interlayer smooths support surface and enables a dense, defect-free PA layer.•Carbon black-enhanced PA layer achieves 50.6 LMH water flux and 0.05 g/L salt flux.•Optimized membrane shows stable performance over 9 repeatability cycles.